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Grouse outlook unclear

Species may be facing survival pressures from new predators and disease

Posted
Thursday, September 13, 2018 9:00 am

Marshall Helmberger

REGIONAL— It’s anyone’s guess what hunters will find when they take to the woods this weekend for the opening of Minnesota’s ruffed grouse season. After last year’s hunt proved less robust than advertised, DNR wildlife officials aren’t making any predictions about the state of the region’s ruffed grouse population.

What we do know is that this past spring’s drumming count in northeastern Minnesota was down from the 2017 count, although at an average of 1.7 drums per stop, it was still above the long-term norm. That means the adult grouse population was certainly high enough this spring to produce a productive season for hunters, but it all depends on their reproductive success and that’s usually a wild card until the season is underway and the leaves start to fall in the woods.

Tower Area DNR wildlife manager Tom Rusch said early field reports suggest average reproduction in northern St. Louis County. Nesting conditions were mixed, said Rusch, with heavy rains in June and July, which can reduced nesting success. Temperatures were mild, however, which should have tempered the negative effects of the heavy rain.

At least some initial reports, albeit anecdotal, aren’t encouraging. “They’re few and far between,” said Dennis Udovich, a bear hunting guide who has been active in the woods around Cook and Orr for the past several weeks.

Grouse numbers have been a source of concern for the past few years, and wildlife managers aren’t sure why that is. Udovich said he’s seen a big increase in the number of raccoons and skunks that have moved into the area, and both species are known to be effective predators of ruffed grouse nests. According to Udovich, every bear bait he put out this year was hit by raccoons. That’s a remarkable departure from the recent past, when raccoons used to be quite rare north of the Laurentian Divide.

“I think the poor grouse are having a tough time,” he said.

At the same time, wildlife managers are trying to determine if West Nile virus could be a factor in the less-than-stellar grouse hunting in recent years. For the first time, DNR wildlife researchers are asking for help from hunters to study the possibility.

West Nile virus is known to exist in the upper Midwest and cases have been found in wild birds, people and other mammals. Birds vary in vulnerability to the virus. Some bird species recover quickly and become tolerant to the virus while others, such as blue jays and crows, suffer higher rates of mortality. The research seeks to examine exposure and active infections in ruffed grouse.

“Although the adult population has been cycling around a stable 10-year average, we don’t know if West Nile might be impacting the production of young birds, which make up a large portion of what hunters see in the fall,” said Charlotte Roy, grouse project leader with the Minnesota DNR. (See sidebar for how you can assist in the research.)

Although the virus has been present in Minnesota for quite some time, a study in Pennsylvania indicated the virus could impact ruffed grouse populations when combined with habitat stresses.

Comments

The last couple of decades you could see the movement of raccoons and skunks northward,especially with longer snowfree periods. Yes exotics like the west nile virus you notice in north central Minnesota with much fewer birds like crows,robins and yes ruff grouse.